Looking for Ways to Save Energy? Try Cleaning Your Plate

That spoiled milk in your fridge is offending a lot more than your sense of smell. Wasted food accounts for as much as 2030 trillion BTU in the U.S. each year. Here's how food waste and energy consumption are connected—and what you can do about it.

Americans are willing to push technology and sometimes their wallets to the limit in pursuit of energy frugality. But saving fuel could be as easy as examining your plate. The power that it takes to grow food, move it around the country, process it, sell it, store it and eventually scrape it into the trash is a major sinkhole in the United States. It accounts for as much as 2 percent of the national energy budget, according to new research from the University of Texas–Austin. If people were more frugal with food, the country could save more power than schemes such as deep offshore drilling or ethanol production would produce.

"In society we seem to be grappling with the energy problem," says Michael Webber, one of the study's authors. "Among the solutions we're searching, food is not one of them. It should be one of the policy options in our toolbox."

Americans waste about 27 percent of their food, according to the USDA. In 2007, the food thrown away required about 2030 trillion BTU, give or take 160 trillion, to make. That's equal to 2 percent of all the energy the nation consumed in 2007, according to the study, or 362.5 million barrels of oil—five percent of the 7.14 billion barrels that the U.S. consumed in 2008 (the latest available figure).

If the country were to waste just 25 percent less food, the savings would be 507.5 trillion BTU, or 90.6 million barrels of oil per year. In comparison, drilling in restricted areas on the outer continental shelf could produce 71.4 million barrels of oil per year in 2030, according to the Energy Information Administration. Reducing food waste by just 37 percent would save the equivalent of 9 billion gallons of ethanol the U.S. produced in 2008.

To calculate the energy lost to the trash, the researchers first estimated how much energy food costs from the farm to the plate. In 2007, that figure was 8080 trillion BTU, give or take 760 trillion—roughly equivalent to 1.4 billion barrels of oil, or 8 percent of the national energy consumption. Next, they used USDA data to calculate that people waste about 27 percent of edible food for human consumption. It's a rough estimate; some of the studies they used date back to the 1970s. And they probably low-balled it: food wasted on the farm and on the road between the farm and the store was left out.

Knowing the kinds of food that people waste is key to learning how to conserve it. Meat production is infamously energy-intensive, but people throw out only 15 percent of it, so it isn't the biggest energy drain. Dairy and grains tie for the most-wasted food groups at 32 percent each. Dairy is more energy intensive, however, so it tops the list as the biggest energy pit at 441 trillion BTU.

Webber recommends an eventual overhaul of the entire production chain, starting with phasing out agriculture on the least-productive lands first. But while policy experts may consider eventually streamlining farms, Cuéllar points out that people can start saving energy now, at home. The time that food spends in the refrigerator and on the stove accounts for about 20 percent of the production energy. "That means that consumers can have a big impact on energy savings when it comes to food waste," Cuéllar says.